Field of the Invention
The invention relates in general to televisions, and more particularly to a technology capable of simultaneously playing multiple television channels.
Description of the Related Art
Various handheld mobile devices, such as mobile phones and tablet computers, have become extremely common in the recently years and are essential information receiving channels in the daily lives of many consumers. To enhance entertainment effects and sharing ability, some video/audio transmission standards have become available to allow handheld mobile devices to project screen images to display systems such as televisions or projects having larger display sizes. One focus among these transmission standards is Miracast™. Miracast™, using a wireless local area network (LAN) as a medium, enables an electronic device supporting such standard to share video images through wireless signals. According to this standard, apart from transmitting video images from a mobile device to a television system for display, a television system may also transmit television program images to a mobile device to display the television program images on a screen of the mobile device. Thus, a user is allowed to view television programs through the compact handheld mobile device.
FIG. 1 shows an exemplary functional block diagram of the above transmission architecture for illustrating signal correlation between a television system 100 and an electronic device 150. A tuner 110 receives external television signals. When a user wishes to view a certain television channel using a video/audio playback device 12, an associated instruction may be transmitted through a remote controller or an external key (not shown) of the television system 100. In response to the instruction, a processor 13 sets the tuner 11 to receive data of a frequency range associated with the television channel, prompts a signal processing unit 14 to retrieve video/audio data of the television channel from an output signal of the tuner 11, and performs processes of demodulation, decoding and image optimization on the retrieved video/audio data. A video/audio playback device 12 then receives and plays an output signal from the signal processing unit 14. A receiving element 15 and a transmitting element 16 operate according to the Miracast™ transmission standard. As shown in FIG. 1, a signal transmission line is provided between the signal processing unit 14 and the transmitting element 16. When the receiving element 15 receives a request for obtaining a television program image from the electronic device 150, the processor 130 controls the transmitting element 16 to transmit the output signal of the signal processing unit 14 to the electronic device 140.
The above architecture suffers from one drawback. That is, an image that the television system provides to the handheld mobile device is synchronous with an image that is being played by the television system. In other words, when the television system is playing a program of a certain television channel, a user using the handheld mobile device cannot opt to watch a program of another television channel.